VitaminRed

What if there was a natural food grown here in Australia that is not only very good for your body but which is a feast to the eye and taste buds. There is such a food. Blood oranges!

The following content is extracted from our Redbelly Health Report on Blood Oranges which was Authored by Kathleen Alleaume.

You can download the full report here:

Or you can download just the 2 page summary with key infographics here:

What is VitaminRed?

Beyond the alluring aesthetics, blood oranges offer health-promoting nutrients and traits that have wide-ranging protective powers. Known for their distinctive crimson-red hue, blood oranges are the only commercially available citrus fruit to contain anthocyanins (which are more commonly found in blueberries, cherries and red wine).

In addition to anthocyanins, blood oranges contain many other beneficial phytonutrients, known as phenolics (or commonly referred to as polyphenols), which have been associated with improved cardiovascular health, cytoprotective effects (UV light, pollution, smoking) and improvements in metabolic disease including type 2 diabetes, fatty liver and obesity. We call unique mixture of anthocyanins and other polyphenols found in blood oranges: VitaminRED®.

When compared with other citrus fruits there are significant differences in nutrients between blood oranges and other orange varieties. These differences are set out in the table below. The tests were conducted using the juices derived from the various citrus fruit as a proxy for their content in the actual fruit (which is an accepted method for investigations concerning water soluble nutrients in citrus) (7A). The data clearly shows that blood oranges have a very high capacity for scavenging free radicals as compared to navel and valencia varieties (9.5x & 6x respectively). They also contain significantly more polyphenols than navel and valencia varieties (3.2x & 2.4x respectively).

Health Benefits of VitaminRED

There are many ways in which VitaminRed may improve the health of the consumer. One of the major ways in which this occurs is via its ‘antioxidant’ effect. However, as many of the studies in this area have shown, the health benefits attributed to the compounds in blood oranges is not soley due to their antioxidant activity. Emerging research is showing these compounds also have anti-inflammatory, anticarcinogenic and several metabolic effects that help protect against cancer cell growth, diabetes, obesity and risk factors of heart disease as set out in the table below.

Metabolic Syndrome, Weight Management & Obesity

Metabolic syndrome is a condition characterised by abdominal obesity, high glucose and cholesterol levels, and high blood pressure – all strong risk factors for type 2 diabetes and heart disease. One study investigated the effects of drinking 750ml of red orange juice over 8 weeks on risk factors for metabolic syndrome. The results spoke for themselves: improved insulin resistance, lower cholesterol and systolic blood pressure. Interestingly, there was no increase in body weight, despite the participants increasing their total calorie and carbohydrate intake per day by 344 cals and 86 grams of sugar respectively. Besides improvements in metabolic risk factors, the study showed that daily blood orange juice consumption does not promote weight gain (9). A landmark study conducted in 2010 found blood orange juice can alter the function of fat cells so they’re less likely to be stored as fat. One group of mice was fed a standard diet with the addition of water, blood orange or navel (blonde) orange juice. The other mice group was given a high fat diet teamed with one of the same three drinking options. Interestingly, mice drinking blood orange juice alongside a standard diet were found to gain less weight and had no affect on both blood sugar and lipid (fat) levels than those drinking navel juice or even water. This is despite the increased calorie intake being received from the sugar content of the juice. Furthermore, blood orange juice was found to significantly reduce or almost completely abolish the weight gain in mice receiving the high fat diet – with a 50% reduction in the belly fat mass being recorded (10). A follow up study was conducted in 2012 in which mice were fed a high fat diet or standard diet and each group was further subdivided into those that were administered water or blood orange juice. Body weight and various biomarkers, including the liver and metabolic enzymes were assessed. With respect to weight, all mice had similar body weights at the beginning of the experiment, however at the end of the 12 weeks, the mice fed blood oranges juice in conjunction with a high fat diet had the same body weights as the mice fed a standard diet and water despite the additional 10% in calories attributed to the sugar in the juice. Interestingly, those mice fed blood orange juice had lower cholesterol and trigycerides and also enhanced insulin sensitivity. In the mice fed water and a high fat diet there was evidence of steatosis (a marker of fatty liver disease).

With the study revealing that blood orange juice can reverse most of the metabolic abnormalities exhibited by obese mice, researchers noted that it may, indeed, represent a promising dietary option for the prevention of metabolic syndrome, including fatty liver, with clinical trials now warranted (11).

While studies conducted on animals show promise, results do not always translate to the same or similar effects in humans. A 2015 clinical study was conducted with overweight human subjects over a 12-week period. The study evaluated the effects of a standardised blood orange extract Morosil®. Results showed blood orange extract can significantly reduce weight, BMI and hip circumference when compared to the effect of a placebo.

The participants in this study received 400mg a day of Morosil® (made exclusively from moro blood oranges). According to the manufacturers website this equates to a dose of about 4mg each of blood oranges hydroxycinnamic acids and anthocyanins, both of which would be available through eating one blood orange a day (12).

Heart Health

A 2017 report published in American Journal of Clinical Nutrition followed 43,880 healthy men and looked at the habitual intake of anthocyanin-rich foods, including blood oranges and the risk of heart disease. The report’s authors note that the bioactive compounds present in both citrus and red or blue fruits appear to decrease vascular inflammation, which in turn keeps blood running smoothly to the heart. This study highlights a potential benefit for protection against cardiovascular disease, however further trials are needed before the exact dose is determined (13). In a 2012 study, 19 non-diabetic patients with increased cardiovascular risks were included in a randomised double-blind study, along with 12 healthy, non-obese control subjects. The treatment group received 500ml blood orange juice a day. After 7 days, blood flow significantly improved and was normalised and several inflammatory biomarkers, including C-reactive protein significantly decreased. These results indicate an anti-inflammatory effect of blood orange that is beneficial to the patient’s cardiovascular system (14).

Dietary intake of anthocyanins may also help protect against high blood pressure (a major risk factor for heart disease), according to a 2011 study. This study suggests an intake between 12.5 to 15 mg per day of anthocyanins in blood orange juice can positively contribute to the reduction of hypertension (15).

While one could argue that the evidence to date is inadequate to define a specific dietary recommendation for anthocyanins and other polyphenols, it’s clear that consuming polyphenol-rich foods, such as blood oranges, should be encouraged.

Anti-ageing

The skin is our body’s first line of defence, meaning it’s continually exposed to a wide variety of chemical and physical attacks, such as pollution, cigarette smoke and the sun’s ultraviolet rays. A 2014 study evaluated the skin photo-protecting and anti-ageing effects of 100mg/daily of a standardised red orange extract. This dose was equivalent to approximately 3mg anthocyanins and 2mg hydroxycinnamic acids, amongst other components. The results showed a significant reduction to the degree of skin erythema (redness), with an average reduction of 40%. Similar protective results were found in the second part of the study, where skin age spot pigmentation was found to decrease from 27% to 7% when subjects were exposed to the solar lamp during the red orange extract supplementation period. Both experiments revealed that the blood orange extract was able to offset the harmful effects of UV radiation – almost like a natural sunscreen (16). A similar study using the same standardised blood orange extract also revealed that the consumption of blood orange extract has the ability to decrease oxidative damage caused by exposure to air pollution and smoking, by increasing one’s antioxidant defences. They attribute this ability not only to the fruit’s anthocyanin content, but also to the complex mix of other bioactive compounds contained within blood oranges used to make the extract (17).

Other Nutrients

Blood oranges are a good source of other nutrients and energy:

Energy. Blood oranges contain just 119kJ (28 cals) per 100g serve of the edible portion. For your average blood orange (200g/150g edible) there is 178.5kJ (42.5 cals) per orange. This represents 2% of the of the average Australian adult’s recommended daily energy intake (RDI) of 8700kJ.

Sugar. The sugars in blood oranges are a mix of glucose, fructose and sucrose (5). They are low GI which makes them an excellent food choice for diets designed to manage weight without compromising on good nutrition (6).

Glycemic Load (GL) is a measure of both the quality (the GI value) and quantity (grams per serve) of a carbohydrate in a meal. Blood oranges have a GL value of 4, which is low compared to other commonly eaten fruit, such as bananas, blueberries, grapes, and apples. This means there should be little fear in adding them to your diet even if you adhere to a diet that is low in carbohydrates (7).

Vitamin C is key for healing and repairing damaged tissue throughout the body and is needed for a healthy immune system. It also acts as an antioxidant and assists in absorption of key minerals, including iron and zinc. Just one blood orange offers 75 mg of vitamin C which is well over 100% of the recommended daily intake (RDI 35 and 45 mg for children and adults respectively).

Beta-carotene. The body converts beta-carotene into vitamin A, an essential vitamin which helps maintain normal reproduction, vision and immune function. An average sized blood orange (150g) has 556μg of beta-carotene which is 92 RE, providing around 10%-13% of the daily recommended intake of vitamin A (RDI 700-900) for adults. Interestingly, this is approximately double the RE available in Navel oranges around four times the RE available in mandarins (6).

Potassium is an essential nutrient used to maintain fluid and electrolyte balance in the body, and prevents high blood pressure. An average sized blood orange provides roughly 10% of the daily recommended intake (RDI) for potassium.